James ward packard



(No Model.)

J. W. PACKARD. METHOD OF EXHAUSTING ELECTRIC LAMP BULBS.

No 401.580. Patente d Apr. 16; 1889.

PETERS. Pholwlilhagrapher. Washinglfim n. c

UNITED STATES PATENT OFFICE.

JAMES WARD PACKARD, OF NEW YORK, N. Y.

METHOD -OF EXHAUSTING ELECTRIC-LAMP BULBS.

SPECIFICATION forming part Of Letters Patent NO. 401,580, dated. April16, 1889.

Application filed April 6, 1888. gerial No. 269,810- (No model.)

To all whom it may concern.-

Be it known that I, JAMEs WARD PACKARD, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in Methods of Exhausting Electric-Lamp Bulbs; and I do hereby declare the following to be afull, clear, and. exact description of the invention, such as willenable others skilled in the art to which it Y appertains to make anduse the same.

My invention consists of an improved method for producing a vacuum inthe bulb of an incandescent electric lamp Without injury to themercury-pumps used in said process and resulting in a vacuum of a highdegree of perfection.

The apparatus with which my method is preferably used is illustrated inthe accompanying drawings, in Which- Figure 1 shows the lampbulbundergoing the first step of exhaustion and resting in a sand-bath. Fig.2 shows the same lamp undergoing the second step of exhaustion throughthe agency of a mercury-pump.

In the use of mercury-pumps in exhausting the contents of the bulbs tobe used. for incandescent electric lamps the main difficulty heretoforeencountered. in obtaining the highest degree of efficiency of said pumpshas been the injurious influence of the moisture and gases within thebulbs upon the mercury of the pump.

The object of my invention is to avoid this difficulty, and thus prolongthe usefulness of the pump, While at the same time a more nearly perfectvacuum is obtained.

In Fig. 1, L" is a lampbulb immersed in the sand-bath S, which is heatedby the flame from a Bunsen burner, H. A mechanical vacuum-pump of anyconstruction may be attached by a hose to the fork 13, which iscontrolled by the stopcock D. In Fig. 2 the three lampbulbs L L L areshown, the fork F being connected by the ground-joint B to themercury-pump A. Connection of the mercury-pump with the fork iscontrolled by the stop-cock C. The mercury-pump is of similarconstruction to that illustrated in patent to A. L. Reinmann and O. G.Ott, granted September 29, 1885, No. 327,313.

to a continuous and equable heat.

In operation my method consists of two steps, as follows: First, thelamp-bulbs L L L attached to tlle fork F, are immersed. in the sand-bathS, as shown in Fig. 1. The first or partial exhaustion of the contentsof the bulbs is then produced by an air-pump of any suitable mechanicalconstruction, While at the same time thebulbs are subjected The cf footof this heat is to drive out all moisture from the bulbs and allclinging gases which might otherwise remain attached. to the innersurface of the bulb or to the carbon. The passage of these gases andvapors through the mechanical pump is, of course, not appreciablyinjurious to it; nor do they in any way decrease its efficiency. whenthe greatest vacuum possible to the mechanical pump has been obtained,the stop-cook D is turned, the lamp'bulbs are withdrawn from thesand-bath, and the end of the fork F inserted in the ground-joint B ofthe mercury-pump A. The stop-cocks B and C are then opened and theexhaustion of the contents of the lamp-bulbs completed by themercury-pump in the usual way.

It is evident that other means of heating the bulb during the first stepin my method of exhaustion may be used, and I do not desire to confinemyself to the apparatus illustrated.

I am aware that Patent No. 251,749, granted to IV. L. Voelker January 3,1882, illustrates and describes a method of and apparatus for subjectinglamp-bulbs to the action of heat before they are exhausted. I am alsoaware that Patent No.26 l,650, granted to T. A. Edison September 18,1882, shows an apparatus for subjecting the lamp-bulb to the action ofheat while its contents are being exhausted by a mercury-pump. Neitherof these employ the method above described by me. The Edison patentshows the very thing I desire to avoid-namely, the passage of vapors andgases through the mercury-pump. In the Voelker process the bulbs areheated before exhaustion; but they may be exposed to the air for anindefinite period before attachment to the pump, and thus everyopportunity is afforded for the admission of atmospheric air with itsusual percentage of moisture.

Having therefore described my invention, the exhaustion of the contentsof the bulb by 10 What I claim as new, and desire to protect by amercury-pump, substantially as described. Letters Patent, is Intestimony whereof I affiX my signature in A method of producing a vacuumin the presence of two Witnesses.

5 bulb of an incandescent light, Which consists,

first, in the partial exhaustion by a meehan- JAMES WARD PACKARD icalpump of the vapors and gases in the Witnesses: bulb, While at the sametime the bulb is sub- A. P. SMITH,

jected to heat; second, in the completion of JOHN J. ENNIS.

